Tech: 1,200-Horsepower Shelby GT500

Big Game

Pro Dyno pumps up John Antunes’ Shelby GT500 with a big-bore 6.2

By Steve Turner
Photos courtesy of Pro Dyno

If you weren’t a Mustang enthusiast, you might assume that a Shelby GT500 with a supercharged 5.4-liter engine would provide more than enough propulsion. We know better. A stock GT500 is fun. A modded GT500 is a blast. However, while most people are happy with bolt-on enhancements and tuning, others want something a bit more aggressive. John Antunes falls into the latter category.

Rather than pulling the stock engine, Pro Dyno built a fresh engine for John Antunes 2008 Shelby GT500. That meant John could keep enjoying his ride until they installed the 381-cube powerplant.

“…I wanted to have one of the fastest street GT500s,” John said.

To bring that plan to fruition, he turned to the skilled crew at Pro Dyno in Fort Mill, South Carolina.

“He came to us a few years ago to build his Boss 302 Laguna Seca; it ended up with a built Coyote with a (ProCharger) D-1 on it. He was more than ecstatic with how that build turned out so we entrusted us with his Shelby build that he had in mind,” Pro Dyno said. “This build has been ongoing for almost two years now. John wanted nothing but the best for this build, with nothing left untouched. A lot of time, money, attention to detail, blood, sweat and tears went into this build for John, to make sure he got the build he would be more than happy with!”